Tear resistant flexible packaging

ABSTRACT

Disclosed herein is a tear resistant flexible packaging for containing material comprising a container formed of a film and having a tear resistant zone disposed adjacent to a seal. A film zone is disposed between the top edge and bottom edge of the container. The tear resistant zone is formed substantially radially around the container. The tear resistant zone has at least one detectable tear resistance that is different from the detectable tear resistance of the film zone. The tear resistant zone directs fears horizontally across the container rather than vertically, eliminating a nuisance tear.

FIELD OF TECHNOLOGY

An improved flexible packaging for containing material and more particularly, a container formed of a film having a tear resistant zone disposed within the film.

BACKGROUND

Flexible packaging is a package or container made of flexible or easily yielding materials that when filled and closed can be readily changed in shape. The term flexible packaging is normally applied to bags, pouches or wraps made of materials such as paper, plastic film, foil or a combination of these. More specific examples of these materials include multilayer polypropylene films, metalized polypropylene, low-density polyethylene film and cellophane.

Examples of industries using flexible packaging are food, beverage, personal care products and pharmaceuticals. Of the aforementioned industries, food is the largest market for flexible packaging. One popular example in the food industry is packaging for potato chips.

The flexible packaging used in packaging potato chips is commonly referred to as “potato chip bags.” Potato chip bags are formed of a film comprising the previously mentioned materials. In the flexible packaging industry the term “film” is generally used to describe a plastic material having a thickness between about 0.0005 and 0.003 inch, but may be a thick as 0.010 of an inch. Potato chip bags are typically formed and filled using a form-fill-seal machine. The bags are filled with nitrogen and hermetically sealed to maintain freshness and to protect the contents during transportation. The purpose of a hermetic seal is to provide a barrier to microorganisms and to prevent oxygen from degrading the food.

The hermetic seal used to form the bags from a film presents a well-known problem: the nuisance tear. The heat seal created on the form-fill-seal machine is difficult to open. The force necessary to overcome the adhesion of the heat seal far exceeds the tear resistance of the film. Once a tear is initiated, resistance to tear propagation in a film is low. If the force applied to open the seal is still being applied once the seal is opened, a tear through the bag will occur, resulting in spilled chips and requiring a new container.

Steps taken to reduce the force necessary to open a seal include a tear notch, however tear resistance in the film is so low that a nuisance tear will still occur. An exemplary embodiment may overcome this problem and provide flexible packaging with a tear resistant zone.

SUMMARY

A tear resistant flexible packaging for containing material having an inside surface and an outside surface comprises a container formed of a film having an innermost layer. The container has a top edge and a bottom edge and at least one seal formed adjacent to one of the top edge or bottom edge. A film zone is disposed between the top edge and said bottom edge, where the film zone has at least one detectable tear resistance.

A tear resistant zone is applied outside of the innermost layer and disposed within the film zone and adjacent to the seal. The tear resistant zone is formed substantially radially around the container. The tear resistant zone has at least one detectable tear resistance that is different from the film zone detectable tear resistance. The film zone and tear resistance zone have detectable tear resistances selected from the group consisting of tensile strength, elasticity, tear strength, cross sectional thickness, cross sectional shape, and toughness.

In an alternate embodiment of the flexible packaging, a tear resistant sore has a fold to form, a reinforcing hem. In one embodiment, the reinforcing hem is bonded to the container. In one embodiment, the reinforcing hem has a fiber in the fold of the reinforcing hem.

Alternate embodiments of the flexible packaging include a tear resistant zone, a bead, a score and fibers disposed between layers of film. In one embodiment, a polymer is applied to the outside surface of the container within the tear resistant zone.

In one embodiment, the tear resistant zone has a detectable tear resistance pattern, where the detectable tear resistance pattern has a relative low detectable tear resistance and a relative high detectable tear resistance. In one embodiment, the tear resistance pattern is embossed. In an additional alternate pattern the embossing forms a crosshatch pattern.

In one embodiment, the flexible packaging for containing material comprises a tear resistant zone that has a strip of material bonded to the film. In one embodiment, the strip of material has a plurality of fibers applied thereto. In an additional embodiment, the plurality of non-parallel filaments form a crosshatch pattern.

In one embodiment, the seal and tear resistant zones have a cross sectional thickness that is greater than the cross sectional thickness of the film zone. In one embodiment, the seal is folded against the tear resistant zone to form a reinforcing hem.

In one embodiment, the flexible packaging for containing material further comprises strap handles bonded to the tear resistant zone. In one embodiment, the strap handles are bonded to a strip of material. In an additional embodiment, at least one fiber is disposed in the tear resistant zone. Alternatively, ring handles may be substituted for strap handles.

Further objects, features and advantages of the disclosed embodiments will become apparent to those skilled in the art from analysis of the following written description, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the claims are not limited to a specific illustration, an appreciation of the various aspects is best gained through a discussion of various examples thereof. Referring now to the drawings, exemplary illustrations are shown in detail. Although the drawings represent the illustrations, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain an innovative aspect of an example. Further, the exemplary illustrations described herein are not intended to be exhaustive or otherwise limiting or restricted to the precise form and configuration shown in the drawings and disclosed in the following detailed description. Exemplary illustrations are described in detail by referring to the drawings as follows:

FIG. 1 is a front view of an embodiment of a tear resistant flexible packaging;

FIG. 2A is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a reinforcing hem;

FIG. 2B is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a bead;

FIG. 2C is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a fiber disposed between layers of film;

FIG. 2D is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having an embossed pattern;

FIG. 2E is a section cat along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a score;

FIG. 2F is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having an additional layer of material;

FIG. 2G is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having fibers applied to a layer of material;

FIG. 2H is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a reinforcing hem applied by an adhesive;

FIG. 2I is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a reinforcing hem with fibers disposed within the fold, the hem applied by an adhesive;

FIG. 2J is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone having a polymer applied to the film;

FIG. 3A is a section cut along 3-3 of FIG. 1 through an embodiment of a tear resistant zone and seal having an increased cross sectional thickness;

FIG. 3B is a section cut along 3-3 of FIG. 1 through an embodiment of a tear resistant zone and seal having a reinforcing hem adhered to an increased cross sectional thickness of film;

FIG. 4A is a front view of an embodiment of a tear resistant flexible packaging having strap handles; and

FIG. 4B is a front view of an embodiment of a tear resistant flexible packaging having ring handles.

For the purposes of promoting an understanding of the principles of the embodiments, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the embodiments is thereby intended. Any alterations and further modifications in the described embodiments, and any further applications of the principles of the embodiments as described herein are contemplated as would normally occur to one skilled in the art to which the embodiment relates.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Exemplary illustrations of a tear resistant flexible packaging comprising a container formed of a film having a tear resistant zone are shown in the attached drawings. A container comprises a tear resistant zone disposed adjacent to a seal. The tear resistant zone directs fears horizontally across the container rather than vertically, eliminating a nuisance tear. A nuisance tear is a longitudinal fear beyond the seal of flexible packaging rendering the packaging unsealable because of the resulting fear. Although embodiments are described as potato chip packaging, it should be understood that the embodiments discussed and described apply to flexible packaging as a whole and not merely to potato chip bags.

As used herein, the term “flexible packaging” refers to containers including, but not limited to, bags, pouches and wraps made of materials such as paper, plastic film, foil or a combination of these. Not intended to be exhaustive, “flexible packaging” is intended to include packaging made from materials, including, but not limited to, multilayer polypropylene films, metallized polypropylene, low-density polyethylene film and cellophane and processes such as biaxially oriented polypropylene (BOPP) and biaxially oriented polyethylene terephthalate (BOPET). The term “film” as used herein refers to plastic material, not more than, about 75 micrometers (0.003 inch) thick.

The way tears occur in packaging is directly related to how the packaging material is made. As an example, paper is made from wood fibers. Trees are chopped into wood chips and the wood chips are mixed with water and chemicals and processed to separate the wood fibers to form pulp. The pulp is pressed on a conveyor belt that squeezes out the water. The conveyor belt also aligns the wood fibers in the direction of the belt which gives paper its grain. Grain is what causes the paper to tear straighter in one direction than another. When paper is torn across the grain the tear works its way along the fibers.

In the case of multilayered films, the tear is believed to relate to the strength of the adhesive. A stronger adhesive will result in a shorter tear. It is believed that is easier to break a film—film bond than an adhesive—film bond. Oriented films provide a significant increase in the mechanical properties of the film, such as Young's modulus, tensile strength, etc., due to the orientation of the molecular chains. Even with improved materials, nuisance tears still result in flexible packaging as a result of the heat seal strength. When a user applies sufficient force to seal suddenly breaking and the residual force ripping through the container.

With initial reference to FIG. 1, a front view of an exemplary embodiment of a tear resistant flexible packaging 1 for containing material is shown. The packaging 1 has an inside surface 4 and an outside surface 6. The tear resistant flexible packaging 1 comprises a container 10, formed of a film 20. Although the film 20 may be comprised of have multiple layers, the film 20 comprises at least an innermost layer 8. The container 10 has a top edge 2B and bottom edge 24. In the exemplary embodiment of FIG. 1 container 10 is a bag 12.

A container 10, such as a bag 12, is manufactured on a vertical form-fill-seal machine (not shown). A film 20 is fed to a form-fill-seal machine which folds the edges of the film 20 together and applies heat and pressure to the outside edges (not shown) of the film 20 to form a longitudinal seal 22. A tube (not shown) is formed by sealing the edges of the film 20 together. Longitudinal seal 22 may be a lap seal or a fin seal.

A bottom edge 24 is formed by cutting the tube while pinching the tube to form a seal 26 along the bottom edge 24 which creates a top edge 28 for the next bag 12 formed. The seal 26 may be formed by any process known the art, including, but not limited to, the application of a heat seal coating or the presence of a heat seal layer as the innermost layer of foil 20. Additionally, the sealing material may be adhesive laminated or extrusion coated onto a non-sealable film (or foil). If necessary for storage of the contents, nitrogen is introduced info the bag 12 and the contents, such as chips or other materials, are disposed in the bag 12 prior to sealing. A seal 26 is formed adjacent to the top edge 28 after filling the bag 12.

The tear resistant flexible packaging 1 comprises a film zone 32 and a tear resistant sore 30. The film zone 32 extends between the top edge 28 and the bottom edge 24 of the container 10. The tear resistant zone 30 is disposed within the film zone 32. The film zone 32 and tear resistant zone 30 have a detectable tear resistance, where “tear resistance” is the ability of the film 20 to resist the propagation of a tear. Tear resistance is measured as the force required to advance a tear as a function of the thickness of the film 20 or tear resistant material 36. As used herein, detectable tear resistance is selected from the group consisting of tensile strength, elasticity, tear strength, cross sectional thickness, cross sectional shape, and toughness.

The fear resistant zone 30 has at least one detectable tear resistance that is different from the film zone detectable fear resistance. The tear resistant zone 30 is formed substantially radially around the container 10 and adjacent to the seal 26. A user typically applies a pulling force sufficient to break the seal 26 to form an opening 29. However, the force to open the container 10 often results in a tear to the container 10 from the residual force, resulting in the nuisance tear sufficiently long and generally along the longitudinal axis of the container 10 to prevent the bag from being sealed. The tear resistant zone 30 causes a nuisance tear to be confined, thus preventing nuisance tear. The tear resistant zone 30 may redirect the tear radially or absorb the residual force causing the tear, negating a nuisance tear.

Referring now also to FIG. 2A, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a reinforcing hem 40. The reinforcing hem 40 is formed by creating circumferential ridge 41 and bending over the ridge 41 against the container 10 to create a fold 42. The reinforcing hem 40 absorbs residual force by causing the hem 40 to come apart. In one embodiment, the ridge 41 of the hem 40 may be adhered to the container 10 by heat, adhesive or any other means known in the art to add further resistance.

Referring now also to FIG. 2B, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a bead 44. The bead 44 is formed of additional film 20 material. The thickness of the bead 44 and change in shape alters the tear resistance resulting in the tear being redirected. In one embodiment, a filament or fiber may be encased in the bead 44 to add tensile strength to the bead 44.

Referring now also to FIG. 2C, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having at least one fiber 46 applied outside of the innermost layer 8 and disposed between layers of film 20. One or more fibers 46, where fibers should be understood to include filaments or other strands of material, may be encased, applied, adhered, welded, rolled or laminated between layers of film 20. The tensile strength of the fiber 46 changes the detectable tear resistance, resulting in the tear being redirected radially.

Referring now also to FIG. 2D, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having an embossed pattern 48. The embossed pattern 48 has a detectable tear resistance pattern, comprising a relative low detectable tear resistance and a relative high detectable tear resistance changing the grain pattern of the film 20. The embossed pattern 48 imposes a grain pattern on the film 20 that causes a tear to be directed radially rather than longitudinally. One embodiment of the embossed pattern 48 forms a crosshatch, providing a gripping surface. Referring now also to FIG. 2E, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a score 50. In one embodiment, the score 50 has detectable tear resistance that is less than the detectable tear resistance of the film 20, causing the tear to travel radially along the score 50, preventing a nuisance tear. The score may be produced by any means known in the art, including by a laser.

Referring now also to FIG. 2F, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having an additional layer of material 52 bonded to the film 20. The material 52 may be plastic, such as flexible packaging material, paper, polyester, or any suitable material known in the art. The material 52 may be bonded to the film 20 by any means known in the art, including an adhesive 54. In one embodiment, the material 52 is an adhesive tape. The increase in thickness attributed to material 52 causes resistance to a tear and therefor the tear is directed radially outward, rather than longitudinally.

Referring now also to FIG. 2G is a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having fibers 46 applied to a layer of material 52. In one embodiment, the strip of material 52 with a plurality of fibers 46 is an adhesive tape. In an additional embodiment, a plurality of fibers 46 are arranged non-parallel to form a crosshatch pattern. The increase in thickness attributed to material 52 as well as the tensile strength of the fiber 46 changes the detectable tear resistance and causes resistance to a tear and therefor the tear is directed radially outward, rather than longitudinally. In one embodiment, the crosshatch fiber pattern resembles a net that extends from the top edge 26 to the bottom edge 24.

Referring now also to FIG. 2H, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a reinforcing hem 40 bonded to the container 10 by an adhesive 54. The reinforcing hem 40 is formed by creating circumferential ridge 41 and bending over the ridge 41 against the container 10 to create a fold 42. An adhesive 54 is disposed within the fold 42 to bond the hem 40 to the container 10. The adhesive 54 in the reinforcing hem 40 requires additional force to come apart, thereby absorbing a higher residual force than without the adhesive 54.

Referring now also to FIG. 2I, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a reinforcing hem 40 with fibers 46 and adhesive 54 disposed within the fold 42. The adhesive 54 in the reinforcing hem 40 creates a stronger bond than the film to film fond, effectively making the film thicker while the fibers 46 increase the tensile strength. The increase in thickness attributed to adhesive 54 as well as the tensile strength of the fiber 46 changes the detectable tear resistance and causes resistance to a tear and therefor the tear is directed radially outward, rather than longitudinally.

Referring now also to FIG. 2J, a section cut along 2-2 of FIG. 1 through an embodiment of a tear resistant zone 30 is shown having a projection 56 applied to the film 20. The project ion 56 may foe formed of a polymer, having improved tear resistant properties, such as toughness, tensile strength, and elasticity. The projection 56 may be applied by any process known in art, including a suitable adhesive to adhere to the outside surface 6 of the film 20. The projection 56 may include an indicia, such as one or more words, symbols or a design. The increase in toughness, as an example, attributed to the mechanical properties of a projection 56 formed of polypropylene, as an example, that changes the detectable tear resistance and absorbs energy causing resistance to a tear.

Referring now also to FIG. 3A, a section cut along 3-3 of FIG. 1 through an embodiment of a tear resistant zone 30 and seal 26 is shown. The tear resistant zone 30 and seal 26 are formed of a film 20 having an increased cross at the tear resistant zone 30 and seal 26. The increased cross sectional thickness changes the detectable tear resistance and causes resistance to a tear and therefor the tear is directed radially outward, rather than longitudinally.

Referring now also to FIG. 3B, a section cut along 3-3 of FIG. 1 through an embodiment of a tear resistant zone 30 and seal 26 is shown where the film 20 is folded over to form a reinforcing hem 40. In one embodiment the hem 40 is bonded to the film 20 to create an increased cross sectional thickness of film 20. The increased cross sectional thickness changes the detectable tear resistance and causes resistance to a tear.

Referring now also to FIG. 4A, a front view of an embodiment of a tear resistant flexible packaging 1 is shown having strap handles 58 secured to a raidially disposed tear resistant zone 30. In one embodiment, the strap handles 58 may be disposed on the front side and the back side (not shown) of the packaging 1. The strap handles 58 may assist a user in opening the container 10 as well as be a convenient carrying handle.

Referring now also to FIG. 4B, a front view of an embodiment of a tear resistant flexible packaging 1 is shown having ring handles 60 secured to a raidially disposed tear resistant zone 30. In one embodiment, the ring handles 60 may be disposed on the front side and the back side (not shown) of the packaging 1. The ring handles 60 may assist a user in opening the container 10 as well as be a convenient carrying handle.

The foregoing discussion discloses and describes the preferred structure and control system for the present embodiment. However, one skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the embodiment. 

What is claimed is:
 1. Tear resistant flexible packaging for containing material, the flexible packaging having an inside surface and an outside surface, said tear resistant flexible packaging comprising: a container formed of a film, said film having an innermost layer, said container having a top edge and a bottom edge and at least one seal formed adjacent to one of said top edge or bottom edge; a film zone disposed between said top edge and said bottom edge, said film zone having at least one detectable tear resistance; and a tear resistant zone applied outside of said innermost layer of said film, said tear resistant zone disposed within said film zone and adjacent to said seal, said tear resistant zone formed substantially radially around said container, said tear resistant zone having at least one detectable tear resistance that is different from said film zone detectable tear resistance, said film zone and tear resistance zone having detectable tear resistances selected from the group consisting of tensile strength, elasticity, tear strength, cross sectional thickness, cross sectional shape, and toughness.
 2. The flexible packaging for containing material as set forth in claim 1, wherein said container has an opening, said tear resistant zone disposed within said film zone and adjacent to said opening.
 3. The flexible packaging for containing material as set forth in claim 1, wherein said, tear resistant zone has a reinforcing hem.
 4. The flexible packaging for containing material as set forth in claim 1, wherein said tear resistant zone has a bead.
 5. The flexible packaging for containing material as set forth in claim 1, wherein said tear resistant zone has fibers disposed between layers of film.
 6. The flexible packaging for containing material as set forth in claim 1, wherein said tear resistant zone has a detectable tear resistance pattern, where said detectable tear resistance pattern has a relative low detectable fear resistance and a relative high detectable tear resistance.
 7. The flexible packaging for containing material as set forth in claim 1, wherein tear resistant zone has a score.
 8. The flexible packaging for containing material as set forth in claim 1, wherein said tear resistant zone has a strip of material bonded to said film.
 9. The flexible packaging for containing material as set forth in claim 8, wherein said strip of material has a plurality of fibers applied thereto.
 10. The flexible packaging for containing material as set forth in claim 3, wherein said, reinforcing hem is bonded to said container.
 11. The flexible packaging for containing material as set forth in. claim 10, further comprising at least one fiber in a fold of said reinforcing hem.
 12. The flexible packaging for containing material as set forth in claim 1, further comprising a material applied to the outside surface of said container within said tear resistant zone to form a projection.
 13. The flexible packaging for containing material as set forth in claim 1, wherein said seal and tear resistant zone have a cross sectional area that is greater than said film zone.
 14. The flexible packaging for containing material as set forth in claim 13, wherein said seal is adhered to said tear resistant zone to form a reinforcing hem.
 15. The flexible packaging for containing material as set forth in claim 5, farther comprising strap handles bonded to said tear resistant zone.
 16. The flexible packaging for containing material as set forth in claim 9, further comprising strap handles bonded to said strip of material.
 17. The flexible packaging for containing material as set forth in claim 11, further comprising strap handles bonded to said tear resistant zone.
 18. The flexible packaging for containing material as set forth in claim 5, further comprising ring handles bonded to said tear resistant zone.
 19. The flexible packaging for containing material as set forth in claim 9, further comprising ring handles bonded to said strip of material.
 20. The flexible packaging for containing material as set forth in claim 11, further comprising ring handles bonded to said tear resistant zone.
 21. The flexible packaging for containing material as set forth in claim 9, wherein said tear resistant zone includes a plurality of non-parallel filaments applied to said material.
 22. The flexible packaging for containing material as set forth in claim 21, wherein said plurality of non-parallel filaments form a Crosshatch pattern.
 23. The flexible packaging for containing material as set forth in claim 6, wherein said tear resistance pattern is embossed.
 24. The flexible packaging for containing material as set forth in claim 23, wherein said embossing forms a Crosshatch pattern. 